We can implement a kind of "internal redirect": replace the merged sense with a kind of "stub" entity including a "symbolic" link to other senses (indicating the content is located in other senses), and existing links will not be broken

Note the individual wikis also have other "meta" pages like user pages; we should decide where we should we import them to. Also note we have T127582: Convert LQT to Flow on wikimania2010wiki. In addition, should we delete and redirect old wikis?

Aug 21 2018

This is not my intention: "Allow add or remove interface-admin group by wikidata-staff" should only apply to their own account, not to arbitary accounts. However I'm not certain whether status quo is bad.

Note "https://www.wikidata.org/wiki/Wikidata:Requests_for_comment/How_to_make_new_languages_enabled_on_Wikidata" says "to add a new label language, add it to MediaWiki"; this is because of they have negative effects. However I doubt how much negative effects it have (why not kill wmgExtraLanguageNames and just use the language-data as the list of available languages). TranslateWiki explicitly don't want to support any ancient language (e.g. Avestan) but Wikidata may like it (especially lemma language is using the same set of label language plus optional -x-Qid suffix, but we clearly should use the ISO 639 code if exist, not mis-x-Qxxx).

Personally I think we should abolish this Wikidata-specific setting. We should just allow all languages in ULS (which will be the same as in https://github.com/wikimedia/language-data/blob/master/data/langdb.yaml) to be used in Wikidata (as monolingual language, label language, lemma language); wmgExtraLanguageNames (in InitialiseSettings.php) should be abolished too.